From owner-freebsd-bugs@FreeBSD.ORG  Thu Sep  4 05:10:13 2003
Return-Path: <owner-freebsd-bugs@FreeBSD.ORG>
Delivered-To: freebsd-bugs@hub.freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id C489A16A4BF
	for <freebsd-bugs@hub.freebsd.org>;
	Thu,  4 Sep 2003 05:10:13 -0700 (PDT)
Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 01A4C43FF9
	for <freebsd-bugs@hub.freebsd.org>;
	Thu,  4 Sep 2003 05:10:13 -0700 (PDT)
	(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1])
	by freefall.freebsd.org (8.12.9/8.12.9) with ESMTP id h84CACUp044329
	for <freebsd-bugs@freefall.freebsd.org>;
	Thu, 4 Sep 2003 05:10:12 -0700 (PDT)
	(envelope-from gnats@freefall.freebsd.org)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.12.9/8.12.9/Submit) id h84CACrV044328;
	Thu, 4 Sep 2003 05:10:12 -0700 (PDT)
Date: Thu, 4 Sep 2003 05:10:12 -0700 (PDT)
Message-Id: <200309041210.h84CACrV044328@freefall.freebsd.org>
To: freebsd-bugs@FreeBSD.org
From: "James F.  Hranicky" <jfh@cise.ufl.edu>
Subject: Re: conf/56031: ipfw hangs on every invocation
X-BeenThere: freebsd-bugs@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
Reply-To: "James F.  Hranicky" <jfh@cise.ufl.edu>
List-Id: Bug reports <freebsd-bugs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-bugs>
List-Post: <mailto:freebsd-bugs@freebsd.org>
List-Help: <mailto:freebsd-bugs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-bugs>,
	<mailto:freebsd-bugs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 04 Sep 2003 12:10:13 -0000

The following reply was made to PR conf/56031; it has been noted by GNATS.

From: "James F.  Hranicky" <jfh@cise.ufl.edu>
To: Robert Watson <rwatson@FreeBSD.org>
Cc: FreeBSD-gnats-submit@FreeBSD.org, admin@cise.ufl.edu,
	freebsd-bugs@FreeBSD.org
Subject: Re: conf/56031: ipfw hangs on every invocation
Date: Thu, 4 Sep 2003 08:01:42 -0400

 On Wed, 3 Sep 2003 11:45:41 -0400 (EDT)
 Robert Watson <rwatson@FreeBSD.org> wrote:
 
 > On Wed, 3 Sep 2003, James F.  Hranicky wrote:
 
 > I'd step up to the ioctl in question, and then see if it really hangs in
 > the ioctl(), or if it gets past and starts spinning.  If it's the ioctl(),
 > it would be very helpful to know which file descriptor it's on, and what
 > the arguments are.  If it's not the ioctl() call, we need to figure out
 > which loop isn't taking something important into account.
 
 I think I've found it. First off, I neglected to mention I've added
 
 	IPFW2=TRUE
 
 to /etc/make.conf, so I'm using ipfw2 (sorry!).
 
 After tracing through, it does seem to be a logic error in ipfw2.c .
 
 At line 1036, there a loop like so:
 
         for (l = rule->act_ofs, cmd = rule->cmd ;
                         l > 0 ; l -= F_LEN(cmd) , cmd += F_LEN(cmd)) {
 
 The loop is supposed to quit when l == 0, and l is supposed to be decremented
 by F_LEN(cmd) each time.
 
 F_LEN is defined as
 
 	#define   F_LEN_MASK      0x3f
 	#define   F_LEN(cmd)      ((cmd)->len & F_LEN_MASK)
 
 Checking the values of the cmd struct:
 
 	(gdb) p *cmd
 	$6 = {opcode = O_NOP, len = 0 '\000', arg1 = 0}
 
 Darn, l is always decremented by 0.
 
 I'll probably fix the problem on my end by temporarily disabling ipfw2 (since I'm
 not really even using it at the moment). 
 
 Hope this helps.
 
 Jim